DNA replicates in a semi-conservative manner in which each individual strand is copied to form a new molecule of DNA. The two strands can be labelled with isotopes using substrates that contain either normal 14N or its heavy isotope 15N. In an experiment, one strand of DNA was labelled with 14N and the other with 15N (hybrid DNA). The hybrid DNA was then allowed to replicate in the presence of the 14N-labelled substrate. If one started with a single molecule of hybrid DNA and allowed it to replicate over 4 cycles, what would be the proportion of double-stranded DNA molecules labelled with 15N?
(A) 1/4
(B) 1/8
(C) 1/16
(D) 1/32
ANSWER PLEASE:85:
(A) 1/4
(B) 1/8
(C) 1/16
(D) 1/32
ANSWER PLEASE:85:
